Proportional remote control



, Aug. 17, 1948. f H. E. HAYNEs y 2,447,121

l PROPORTIONAL REMOTE CONTROL Filed DBG. 10, 1943 Bnventor HHRULD E.HHYNE5 Patented Aug. 17, 1948 rBoroa'noN/u. amore coN'raoL Harold E. Haynes, Indianapolis, Ind.. assigner to Radio Corporation of America, a corporation of Delaware Application December l0, 1943, Serial No. 513,194

Claims 1 This invention relates to proportional remote control or telemetric devices and more particu.

larly to the use of control tones to fix the position of a pointer or other device.

In the prior art control tones have been used for the same general purpose. The control tone which produced vthe deflection of the pointer .or other device was transmitted through some appropriete transmission system and at the end of the transmission system produced its effect upon the pointer or analogous device. The amplification of the transmission system, however, varied and in order tosecure accurate deflections a second constant amplitude control tone had to be transmitted over the same transmission system and this was used to control the amplification of the system so that the first control tone was reproduced at nearly constant relative amplitude.

In this invention the variable amplitude control tone is transmitted over the transmission system and concurrently therewith a different frequency control tone of -unvarying amplitude is transmitted over the system as in the prior art. The rectified output of the unvarying amplitude tone as transmitted is bucked against the output of the varying amplitude as transmitted in a potentiometer and the Vdifference voltage vis used to control the pointer or other device and to control the movement of the contactor on the potenti,- oxneter. This gives the result of a proportional movement of the pointer but avoids any amplification control.

One object of the invention is to provide a control device in which the movement of the member controlled is proportional to the movement of .the control member.

Another object of the invention is to provide a control device in which the movement of the member controlled is directly proportional to the movement of the control member,

Another object ofthe invention is to provide a remote control device in which the transmission system may Abe. a sound record film.

Another object of the invention is to provide a remote control device in which the power exerted by the control means may be many times as great as the power exerted by the controlled member.

Other and incidental objects of the invention will be apparent from a reading of the following specification and an inspection of the accompanying drawings in'which:

The single figure of drawings isya schematic diagram of my device.

Referring to the drawing, Il represents a source (ci. :1s-2s) of alternating current of arbitrary frequency c which is adapted to be transmitted by the transmission system. This current is applied to potentiometer I2 and the movable contact I3 is moved l along the potentiometer in accordance with the .motion to be transmitted. The contact I3 may, for example, -be moved in accordance with a pointer, a gunsight, or other indicating device.

il I represents a source of a different alternatl ing current which, for convenience, may be called p which is at a different constant frequency and a constant amplitude. The frequency p should be separable from the frequency c by appropriate means such as band pass filters, or one might be transmitted by a high pass filter and the other transmitted by a low pass filter. The output of the device I I and the output of the potentiometer I2 are added in a mixer m and transmitted to a transmission system- I5.

' This transmission system may be of any desired type. For example, the frequencies may be recorded on film by conventional sound recording means and thereafter reproduced from the film by conventional reproduction means, or the frequencies may be transmitted over a conventional electric or acoustic transmission line. After transmission the frequencies are separated by appropriate filters. For example, Il, also labelled Fp, is a filter possibly of the band pass type transmitting the frequency p, and I9, also labelled Fc, |is a filter possibly of the band pass type transmitting the frequency c or the control frequency. The alternating voltages are both rectified in appropriate rectiflers marked I8 (Rp) and 20 (Re). It will be apparent that the transmission system I5 may include amplifiers so that the output of the lters and rectiflers will be sufficient to accomplish the necessary purpose. It is undesirable to', include separate amplifiers after the current reaches the separating means as these separate amplifiers will have to be cross-connected in order to secure the same degree of amplification at all times.

The output from Rp is applied across the potentiometer 2l, where it establishes a definite, but not necessarily unvarying, potential drop across the potentiometer. The output Re is fed through the winding 24 of the relay 23 and applied by the movable contact 25 to the potentiometer 26. The

50 relay23 is for convenience shown as a polarized relay handling the entire current from one winding of the motor l I. This winding, of course, may

be either the armature winding or the field winding. The motor and reduction gears will be furu ther described hereinafter. If the potential at the movable contact 25 is equal to the potential on the potentiometer at the point where the movable `contact rests, the amature of the relay is not moved. If the potentials are unequal, the armature of the relay 23 will be moved in one direction causing the motor 2| to rotate and through the reduction gears 22, causing the contactor 25 to move along the potentiometer until the potentials are equal when the circuit through the relay 23 is broken. If the potentials are unequal in the opposite direction, thearmature of the relay 23 will be moved in the opposite direction producing an opposite movement of the motor until the potentials are again equal.

It is not necessary that the potential applied to a potentiometer 26 by unvarying as inthe prior art devices. In my arrangement the rectified potential indicated by Rp and the control potential indicated by Re are always proportional Whatever their' absolute values, and it is this proportion which, determines the position of the contactor 25 and the position of the pointer or whatever other device is operated by the motor 2l.

` The motor 2|` may be of any desired type. In

thedrawing itis illustrated as a'D. C. motor with..

the direction of current through one of the windings reversible by the relay 23. It is clear that instead of using a single polarized relay 23, a plurality of relays may be operated by this first relay, and as the relays may have any desired current carrying capacity the motor 2l may be of any -system for transmitting said'imixedoutputs,

1 means for separating and rectifying the alternatdesired size. For example, two-phase alternating current can be supplied to the motor 2l and one of the phases reversed by the relay system, and

the same thing applies to three-phase alternating current with its usual reversing system. If a. small motor is to be used this motor may be D. C. as indicated in the diagram, or it may be a singlephase capacitor motor or some equivalent type of y reversing. A. C. motor.

It will be apparent from the foregoing that the .contacter is always located on a potentiometer 26,1n a definite proportion to the position of the contacter I3 on the potentiometer i2 regardless of what type of transmission system is used and regardless of what type of motor drive is used.

I claim as my invention:

1. A telemetric system including two sources of alternating current of constant amplitudes and of different frequencies, means for selecting a portion of the potential of one source, means for mixing the output of one source and the 'output of selecting means, a transmission system for transmitting said mixed outputs, means for separating land rectifying the alternating currents corresponding to said frequencies at the output of the transmission system, means for applying current from the constant amplitude source across a potentiometer, contact means for applying the variable potential to the potentiometer, and means for moving the contact means in accordance with the current fiowtherein.

ing currents corresponding to said frequencies at the output of the transmission system, means for applying 'current from the constant amplitude source across a potentiometer, contact means for applying the variable potential to the potentiometer, and means for moving the contact means in accordance with the current flow therein.

. 3. A telemetric systeml including two sources of alternating current of constant amplitudes and of different frequencies, a potentiometer bridged across one source to secure la variable potential, means for mixing the output of one source and the output of the potentiometer, a transmission system for transmitting said mixed outputs. means for separating and rectifying the alternating currents corresponding to said frequencies at the output of the transmission system, meansfor applying current from the constant amplitude source across a potentiometer, contact means for applying the variable potential to the potentiometer. a motor for moving the said contact means, and means for controlling the direction of the rotation of the motor in accordance with the current flow through said contact means. 4

4. A telemetric system including two sources of alternating current of constant amplitudes and of different frequencies, means for selecting a l flow .through said contact means.

HAROLD E. HAYNES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

